text:
When Boeing designed the 737NG, what factors influenced the change in the flap system?
The early Boeing 737 models had wings with triple-slotted flaps that appeared to be derived from the 727. When the 737 was redesigned as the Next Generation series (dash 600 through 900), these flaps were dropped in favor of a double-slotted design.
Why did Boeing choose to make this change, and what were the trade offs? Did it impact performance? I had always been under the impression that early 737s were reasonably capable on shorter and rougher runways.

One of the biggest differences that you will see between the flaps on the two is that the NG (photo on the right) has continuous span flaps while the classic has split inboard and outboard flaps.

Combined with the longer wing on the NG, this gives the new flaps more surface area, so they don't need to be quite as effective.  Overall, the NG actually has better performance than the classic, mainly because of the redesigned wing which is 25% larger and has winglets; both of which help out.
Even though the performance is better with comparable triple-slotted flaps, the double-slotted flaps are lighter (which helps with overall aircraft performance) and have fewer moving parts.  This makes them more reliable and they require less maintenance.  Most new aircraft designs are moving to either double or even single slotted flaps because of this simpler design and the fact that today's runways don't require the extra performance that would be gained by the more complicated flaps.

Photo Credits:
737 Classic Flaps
737NG Flaps

Don't double-slotted flaps have less drag for the same lift (though maximum lift possible is less)?

@Qantas94Heavy Yes, double-slotted flaps have less drag and less overall lift than triple-slotted flaps, both of which are positive design factors for the triple-slotted flaps.  (When putting flaps down for landing, drag is a good thing in a jet!)


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What is this device on the nose of a Bombardier Global 6000?
What is the circled object?

(jetphotos.net)

@ymb1 I really wish they'd have had that system back when I was able to jumpseat. That would've been cool to watch.

That is the sensor for the aircraft's Enhanced Vision System (EVS) - a combination of a visible low light and infra red video cameras which are combined together via computer into a composite image for display on either the PFDs or HUD in the cockpit.  It provides better situational awareness in poor visibility and during night operations for the crew.  See demonstration video here, and a video for how it can light up high terrain here (frame below):

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text:
How do the FAR's define a cloud?
If you're talking about a big puffy cumulus cloud it's pretty obvious. But from where I am right now, looking up I see grey sky from horizon to horizon. But visibility at the surface is good. All nearby metar's are reading 10SM CLR. It's just a tiny bit hazy, but I can clearly see a water tower that is 8 miles from me. But there is no defined cloud layer. It just seems that the haze gets thicker the higher you go. If there was a vfr plane up there at a few thousand feet I'm sure I could see it but I can't see any of the four airliners that FR24 shows are above me.
My question is, when there's no defined cloud layer, what is considered "cloud" and what isn't? If the minima require you to stay 500 feet below clouds, where exactly is that? With metars showing no ceiling how do you know where it is safe to fly and where there might be an ifr flight descending that can't see you?

I don't know about the FARs, but my instructor told me, "If you can see through it for a distance of 3NM (or visually down 500 ft, or visually up 1000ft), then its not a cloud; its just some moisture."

My CFI pretty much mirrored what @abelenky 's CFI did, "if you can see through it, don't worry about it".

"That's not a cloud - that's a region of temporarily reduced visibility."

My question is, when there's no defined cloud layer, what is
  considered "cloud" and what isn't? If the minima require you to stay
  500 feet below clouds, where exactly is that? With metars showing no
  ceiling how do you know where it is safe to fly and where there might
  be an ifr flight descending that can't see you?

The FAA defines clouds in AC-006B

A cloud is a visible aggregate of minute water droplets and/or ice
  particles in the atmosphere above the Earth’s surface. Fog differs
  from cloud only in that the base of fog is at the Earth’s surface
  while clouds are above the surface. Clouds are like signposts in the
  sky that provide information on air motion, stability, and moisture.
  Clouds help pilots visualize weather conditions and potential weather
  hazards.

However legally and practically speaking you can fly as high as you like if there are no clouds provided you can maintain situational awareness and proper cloud clearances from any adjacent clouds (including those under you). There are a few practical limits to this. First off Class A airspace starts at FL180 so you cant fly above 18,000 Ft. without being on an IFR flight plan since you cant fly VFR into class A. Further more, since you seem to be asking about small aircraft, you will more than likely be limited by your airframes maximum altitude before hitting the Class A limit. You will also need O2 onboard to fly above 12,500 ft.
The risk of a descending aircraft above you is always a concern be it VFR or IFR flying as they generally cant see below them and you cant always see above you when flying. In many cases the IFR flight will have some help from ATC who will see you on radar even if you are flying VFR and squawking 1200 on your transponder.

In the US, only student pilots need to maintain sight of the ground. Once you have your PPL, you can fly over cloud cover—I do it all the time. It even has a name—VFR Over-the-Top. I don’t believe that there is a requirement to maintain visibility with the horizon for either student or PPL.

You are correct that you can fly Over-the-Top, the horizon issue is somewhat addressed in this question Something made me think you also needed to see the ground but im looking into it now. You may in-fact be correct. However not being able to see the ground or the horizon may be considered IMC.

As long as you are in VFR conditions (§91.155   Basic VFR weather minimums.), a PPL can legally fly VFR. However, it is possible to be flying on instruments, and even log IFR time, in VFR. Imagine a moonless night above the clouds or out in the boonies. No horizon, no view of the ground. You may need to fly solely by reference to instruments. That would count as instrument time for your logbook, but you would not need to be on an IFR flight plan since you are in VFR meteorological conditions.

The only reference to seeing the ground that I am aware of is Subpart C—Student Pilots §61.89   General limitations. (7) When the flight cannot be made with visual reference to the surface; or

By "VFR flight conditions" you mean VMC?

I do mean VMC, I can change it if need be. I did some digging and I cant find anything about the ground however it does seem that there may be some non FAA/USA regulations around this, I found some Canadian regulations that may require it but have not yet finished digging into them.

This is one of my pet peeves: When talking about the conditions (moonless night, etc), it should be important to call them either VMC or IMC. When talking about rules, it's VFR or IFR. You must be in VMC to operate under VFR rules. This should not be referred to as "VFR Conditions", because you can also operate under a different set of rules (IFR) in those same conditions (VMC).  Unfortunately, even the FAR and AIM both use the term, "VFR Conditions" -- which in my opinion is a term that needs to be nixed from all literature. Too much confusion has been had by intermingling terms.

@Jimmy  Most of the time it is clear what is meant, but you are right, it does occasionally lead to confusion. I count 15 times it is used in the AIM. It is also used in Aviation Weather Services, Aeronautical Decision Making,  Instrument Flying Handbook, Risk Management, Airplane Flying Handbook, Aviation Instructors Handbook, Airplane Flying Handbook, Instrument Procedures Handbook, Pilots Handbook of Aeronautical Knowledge, and the Pilot Controller Glossary. And at least 10 times in the FARs. So I doubt that it will ever be nixed.

@jscarry, you're right, it's a futile expectation. And my "rant" didn't add anything to this Q&A. To sorta get back on topic: you mention "logging IFR time". This is another confusing term because (afaik), you can only log "instrument" time (that portion of the flight when you are controlling solely by reference to the instruments).  Conducting an IFR flight entirely in VMC means you cannot log "instrument" time, but the phrase "logging IFR time" implies that you would log the entire flight (having been under IFR rules the whole time). (which, I believe, they do in Europe - log "IFR time")

@Jimmy, can you not log instrument time in VMC with a proper view limiting device?

@Jimmy §61.51   Pilot logbooks. g) Logging instrument time. (1) A person may log instrument time only for that flight time when the person operates the aircraft solely by reference to instruments under actual or simulated instrument flight conditions. Note that the FAR does not say instrument flight rules, just instrument flight conditions. I don’t see that term defined, but in the context of the rule, I assume it means "as if you are flying under instrument meteorological conditions" i.e. you can’t get cues to your position or orientation from outside the cockpit. BWTHDIK

I found the reference, there is a book called "FARs Explained" where I got my interpretation. They base it on an FAA Chief Counsel letter to Joseph Carr in 1984. I can’t find the letter, but I found a transcript of it. http://forums.jetcareers.com/threads/logging-actual-under-part-121.74365/ The relevant part is "actual instrument conditions may occur in the case you described a moonless night over the ocean with no discernible horizon, if use of the instruments is necessary to maintain adequate control over the aircraft. The determination … is somewhat subjective…"

Thanks, @jscarry, and good reference!  My comment was only on the phraseology that you used: "IFR time". My statement was that "Instrument time" is the more correct term. In the US, pilot's don't log "IFR Time", because that phrase implies any flight where they are on an IFR flight plan and under ATC control. The entire flight would be considered "IFR Time", but not necessarily "instrument time". US Pilots only log "Instrument Time" during meteorological conditions met in 61.51, no matter if they are on an IFR flight or VFR flight. (and the caveat that I believe Euro pilots do log "IFR Time")

@Dave yes, pilots are allowed to log "simulated instrument time" when they are using a view-limiting device in VMC and under the supervision of a safety pilot.

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Can Air planes fly through rainbows?
I am wondering whether or not it is possible for an air plane to fly through a rainbow, and, if so, does anyone have any pictures or experiences of what you can see?
I've always been intrigued by this.

Why cant fly though rainbow?

This question belongs on SE.Physics but the short answer is no.  A rainbow does not exist.  It's an illusion caused by refraction of light rays.  The observer must always be between the light source and the rainbow.  Imagine the conditions are right for the rainbow to exist for ever.  You would also travel for ever trying to reach it.  Incidentally, all rainbows are circular.  It's just that most of the ones we see are interrupted by the ground. https://en.wikipedia.org/wiki/Rainbow

Better posed on earthscience.se or physics.se , but ^^^ is the answer.

@Simon: So you say there is no pod of gold where  the rainbow touches the ground? :-( Seriously: That myth exists because you can not prove it, as you can never reach that point:  It just does not exist. For the same reason, an aircraft will never fly though a rainbow, even if it seems so for an observer on the ground.

I have a side question making this question more aviation-related: On ground, a rainbow is a half circle, well, because there is ground. For a flying observer, a rainbow could form a full circle. Has anybody ever seen this effect?

@sweber Yes.  I've seen one.  The point about an observer is strictly incorrect since no 2 people can see the same rainbow.

@sweber Yes.  Search images for "full circle rainbow plane" and you'll find many such examples.

Flying inside a rainbow is not recommended as it can destroy the aircraft external skin.

Possibly one of the best questions I've seen on this forum.  Also, can Air planes fly faster than unicorns?

On first reading the title I thought it was about a new Canadian airline.

Of course they can a rainbow is reflecting light from the sun anything could go through a rainbow

@mins I love this comment!

Unicorns can. When they do it creates a pot-o-gold at one end. This P.O.G. attracts Leprechauns. When the Leprechauns get that POG the rainbow disappears. Then the Leprechauns go to the nearest pub (after changing their clothes so as to not attract attention) and spend that POG. When the POG is empty the Leprechauns stagger out of the pub and barf. This post-pub-crawl ritual creates a rainbow which attracts unicorns ...  That the pub crawl happens at night explains why we never see unicorns.

Depends on what you mean by fly through. I flew under a rainbow once. I was flying a tactical jet over the Mediterranean when I saw a full rainbow from horizon-to-horizon in the distance. Thought about it for a second, and realized I will never get this chance again, and so off I went. As I approached it I watched the ends come together from the horizons. By the time I got under the rainbow it was a full ring around the A7E. Did an aileron roll to check it out. Very cool experience. Always thought that the Leprechauns were very clever to hide their gold at the end of the rainbow.

A rainbow is created by refraction of sunlight so you have to be in the right position to see it. The effect is only created at some distance. A rainbow that you see from the ground may appear to be in a particular place in the sky. An airplane could fly through that space and it might appear to you that it is passing through it The occupants of the airplane, however, would not see a rainbow there.

The physics forum might yield a better answer since this is really a question about optics. Besides, I was working hard not to be funny and say they would crash into 'em.

Running into a rainbow is hard, whether walking, driving, or flying.  The reason is that rainbows are not objects - they are an optical illusion that only exists in the eye of the observer.
Trying walking toward a rainbow.  You'll find it moves away, and eventually disappears.  This is one reason why you'll hear people say there's a pot of gold at the end of the rainbow to describe wishful thinking.  You can never get to with end of the rainbow - the more you move, the more it moves.
Being an optical illusion, it has absolutely no impact on other physical objects.  So if you are on the ground, you could observe an airplane flying through a rainbow that you see.  The pilots on the flight would not see the same rainbow you see, and would not be able to tell that they are flying through the optical illusion you are experiencing. They would, however, encounter the water that is creating the illusion for you.  Fortunately most planes have no problem flying through mist or rain, and thus there is no problem.
The reason you rarely see photos of planes flying through rainbows is that few pilots enjoy flying through the weather that creates these illusions, and try to avoid them by flying over or around the situation that would create a rainbow.

I once saw a rainbow that terminated over Centre 1, East Kilbride, famous in the UK as the headquarters of Inland Revenue. Yes, I did get quite a nice income tax rebate that year.

From the air, rainbows are circular!  Not just merely the arch you see from the ground. We've seen some nice ones flying in a small plane at lower altitudes.


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What is the best word for lateral translational movement in a rotorcraft?
I'm talking about movement left and right without changing attitude. This is a motion that can be done with a quadcopter and to a limited extent a helicopter (I presume).
On a helicopter a left/right movement of the cyclic will command a roll motion from the rotor, but in a hover the aircraft would only roll slightly then begin to move sideways. Does the pilot just call this a roll or is there another, more appropriate word?
I thought of slip or crab, but those describe specific attitudes associated with forward flight. They don't seem to fit the bill here.

In the standard 6-axis terminology this is called Sway. I have no idea if there's special helicopter terminology.

Are you asking what a pilot uses to describe sideways flight?

@Simon Looks like the term I'm looking for is sway. I've never heard that term before. What do you call sideways flight?

"Sideways flight" :)  Technically known as "translating".

A quadcopter can't move sideways without changing attitude at least slightly, unless the lateral movement is caused by the movement of the air (wind).

The answer is in the question: lateral, fwd/aft is longitudinal. The cyclic stick directions are cyclic longitudinal and cyclic lateral: move the stick and the rotor tilts, producing direct translational movement. The helicopter fuselage follows the rotor angle and therefore pitches/rolls as well, but more as a (desired) side effect. Desired because they enable instant judgement on the amount of stick applied. In a fixed wing, stick fwd/sideways is pitch stick and roll stick, because stick inputs primarily affect the aircraft attitudes. Longitudinal and lateral are helicopter terms because stick inputs (in a hover) mainly affect translations. And yes on a 6-DoF simulator motion system they are called Surge and Sway.

In a helicopter, longitudinal and lateral are only used when referring to the airframe for example when calculating CofG.  The attitude is always described as pitch, roll and yaw - the same as aircraft.

Yes the attitude is pitch roll and yaw, same as in a fixed wing aircraft. But the helicopter cyclic stick sideways is not called Cyclic Roll, it is called Cyclic Lateral.

Have made the answer more concise.

I have never heard from my instructors, QFIs or other pilots anything other than left/right or forwards/backwards (fore/aft) for cyclic input.

Well that makes sense, longitudinal is kind of an inconvenient word to use. It was mentioned that way in the technical documentation of a couple of helicopter flight control projects I did in the distant past. Maybe it's only used in fancy brochures, or in the USA.

The term I preferred was "slide"
In our NATOPS manuals, and in our trained procedures in both Search and Rescue ops, and cargo ops, in the Navy the crewman would call for us to "slide left" or "slide right" as he positioned us over the pick up point.  (Easy Left/Easy Right as we got closer to the spot).
The FAA term "sideward hovering" suffices, but it is two words.  If you want one word, slide is about right.

Was unsure which answer to accept. I decided on Koyovis' answer because the technical term I think I was looking for was sway. But slide would make more sense to the photographer I'm working with, so I'll be using your term. +1

@TomMcW Glad to be of help.

The FAA Helicopter Flying Handbook discusses maneuvering in chapter 9. This movement is called a sideward hover.

Sideward hovering flight may be necessary to move the helicopter to a specific area when conditions make it impossible to use forward flight. During the maneuver, a constant groundspeed, altitude, and heading should be maintained.

There are also the forward and rearward hovers, and the hovering turn. These hovers are probably all specific to helicopters, where straight and level flight is designed to be performed in the forward direction. Aircraft like quadcopters are less directional and can generally fly "straight and level" in any direction relative to the quadcopter.


text:
Can state or local laws regulate where aircraft can take off and land?
Say you have as private strip, but your neighbors get tired of hearing your plane. Can the local authorities pass, and enforce a law saying you can't take off and land there? Or do FAA rules override local authority as to where you can and can't land?

Related

I think Rick Durdan's article regarding Colorado state's laws restricting seaplane use of waters within that state is pertinant: Seaplanes in Colorado: Fighting for Access

As any licensed pilot knows, the FAA and the US military are the "de-facto" regulators of 99.9% of what goes on in the air over the US (see: https://aviation.uslegal.com/government-regulation-and-control/state-aviation-regulations/ ).  Still, state and local governments are not entirely powerless here.  The general theory being more or less that, in cases where there is no obvious conflict with the FAA, or the US military, then local jurisdictions may still have some small level of control over certain very limited "air-spaces" (see: http://caselaw.findlaw.com/us-6th-circuit/1140229.html ).  Suggestion: 99.9% of the time, the FAA wins, but hey, don't let that slow you down!  (Still, in view of the findings of the second case I just listed above, if I were you, I might try keeping peace with my neighbors over trying to save just a few steps on the way home.)

The court in Gustafson did a pretty thorough job of smashing federal preemption!

If my next door neighbor tried to declare his back yard as our town's greatest and newest heliport, I'd might feel like smashing one or two things too! :-)

One reason I was wondering is because there's a small community in my area that is built around a grass strip. It's out in the country - for now. The growth in that area is become rapid, so I could see it becoming enveloped by suburbia next 10-20 years. There's a pattern of the municipalities annexing big chunks of county land against the residents' wishes.

My experience with local government is "squeaky wheel land owner groups" often get the "oil."  If the folks around that air strip want to keep their airstrip as an air strip, they had best keep a presence in local municiple public meetings, and had better be prepared to mobilize a "group of concerned citizens" to also attend on short notice and as needed at the local muni meetings.  As they say in law, "silence (seems to) imply consent."

@ScottFrancisPerry indeed. And be prepared to be constantly shouted down by "environmentalists" screaming that "those filthy aircraft owned by the Rich should be banned from our community" to great applause from the media.

If you want to hear an interesting story of the FAA standing up for a private grass strip read my answer to this question

Civil Helicopter Operations are greatly stilted by local county, and municipal laws that in many cases, prohibit helicopter operations. In cities where a public helipad has been established, flight operations are often severely restricted by annual movements, or specific hours of operation. With that said, here is an extract from a piece written by Matt Thurber for Business Jet Traveller Magazine, in October 2010:

The FAA doesn't prohibit helicopters from operating most places, so you should be able to land one in your backyard if you can do so safely. And no law says you have to build a helipad to land. The regulations do, however, "require notification to the FAA for any permanent landing area; private versus public use does not matter," according to FAA airports airspace specialist Angie Muder. City, county and state requirements may present greater obstacles, so be sure to check these, too.

Say you have as private strip, but your neighbors get tired of hearing
  your plane. Can the local authorities pass, and enforce a law saying
  you can't take off and land there?

The short answer is yes they can. You are allowed to build such a strip as is answered here. However the city may have a thing or two to say about it and there are things they can do. A lot of big cites have noise abatements that prevent aircraft from being bothersome. In reality they legally could have the noise abatement be in effect all the time preventing you from ever flying in and out of your strip. An appeal to a higher court may rule in your favor on a case like that. However towns can have all sorts of strange regulations that may prevent you from storing an airplane on your property like this case from LI NY . Some states may chose to not regulate it like Kansas at a state level,

Kansas has no inspection program and makes no apologies for allowing
  private airport owners to operate free of bureaucracy. "We in Kansas
  love the sound of aviation," says Mike Armour of the Kansas Department
  of Transportation.

There are lots of jurisdictions here in the US and it will vary heavily from one to the next.

Or do FAA rules override local authority as to where you can and can't
  land?

Generally no, however the airspace in this country does fall under the federal purview and you are allowed to use it as long as regulations are followed. With that in mind the FAA sure does have a lot of regulations about where you can't land but generally does not mind you landing on your own property. In some cases the FAA may even be on the cities side such as we have tragically seen in the case of the Santa Monica Airport.

Actually, FAA regulations preempt local noise ordinances. The only reason airports can enforce noise rules is through property rights. In other words, if the city owns an airport they can enforce noise regulations as proprietor of the airport. But a city can't enforce noise regulations for private airports. Federal exemption applies specifically to noise ordnance.


text:
What is the section of the fuselage below the wings called?
Is there a specific name for the protruding section of fuselage beneath the wings? Im talking about the area where the landing gear bay often is. In the photo it's where the red Emirates logo is painted.

source
Some older airliners don't have them, such as the A300

source

I think most people call it "the belly" though there may be a technical term for it.  I would call it the "belly center section" put that's just pilot talk and may not mean anything to anyone who builds or maintains these planes.

@acpilot I figure it's got some kind of fancy French name, like "renflement," or "gonflement." I would choose "ventre de bière" myself.

I wonder the same. Really pronounced on many business jets like the Citation X.

Ventre de bière it is!  Now, we need to Americanize it so...it's a "venter dee beerie."

In the trade this part is generally called "belly fairing" because that term is shorter and more specific than older names like "center wing fairing" or "wing-to-body fairing" or "wing/fuselage fairing". See this AV article about an AD for the A380, for example.
Belly fairing expresses better that the fairing is mostly below the wing-fuselage intersection. The older expressions were already used for the usual fillets between wing and fuselage which became standard in the 1930s. When it was learned that in transsonic flow the clever shaping of displacement bodies can reduce drag, the fairing grew over time. An important benefit is the added space for storing the main gear.
The usual French name for it is "carénage ventral", which is a pretty straightforward translation of the English expression.

"carénage ventral" in my Frenglish becomes "belly carnage" which isn't really what we're after, is it?  :D

The outer covers at-least, are called wing to body fairings in this Airbus document- 'Airbus Future Composite Wing'.

Wing to body fairings; image from Airbus Future Composite Wing
Elsewhere, the covers are called belly fairings by the manufacturers themselves, and also in the US patent US 20060065784 A1- Aircraft provided with a belly fairing, and corresponding belly fairing.
Anyway, the fairings enclose the center wing box and the main landing gear wheel well.

Finally is a fairing of the junction between both components, fuselage and wing. The intention of this fairing is to reduce the drag created by the junctions. Essentially this fairing is located in the "belly" of the airplane.
So, the usual name is "belly fairing".

Or wing-to-body fairing.

this fairing is located in the fairing. ??

This answer is hard to understand. Could you clarify your meaning?

Arg... wrong spealling, sorry.


text:
Are transponders sometimes referred to as ‘parrots’?
Looking at the A/FD for Anchorage Ted Stevens Intl (PANC), there are a couple of entries in in the airport remarks for a piece of onboard equipment called a ‘parrot’.

I am not familiar with this piece of equipment aboard an airplane, though I suspect it may be a synonym for a radar transponder.  Has anybody heard that term for a transponder as well?

Because NATO code word for IFF is Parrot. The codewords are somewhat of a misnomer since they are more about standardizing usage and removing ambiguity ('parrot' is hard to mix up with other aviation terms) than being a true code, though as here can be confusing to outsiders wondering where the animal, mythical creature or alcoholic drinks names are coming from.
Have vague memories of seeing British WWII usage but not currently finding a source using Parrot that far back, where it would more likely to have had an actual code word, randomly selected for NOT having meaningful association with interrogate/response.

Brevity terms aren't any real secret; they're published so that all NATO pilots use the same words meaning the same thing, and they're widely used in training & daily operations. They also have enough association with the underlying term as to be easily remembered... you don't want to be struggling to remember an arbitrary term in the middle of a tactical exercise. This discussion is a good example: a parrot squawks to announce its presence.

https://hartzellprop.com/brief-history-5-atc-terms/ isn't a great source but also says it's RAF terminology.  If a system was codenamed Parrot (in the usual sense of code names) the natural verb for its transmission would be "squawk*.  I reckon if the RAF's IFF system had been called duck, transponders these days would quack

"Code" doesn't even mean secret, necessarily. Consider Morse code. So I'd say this isn't a misnomer but just another example of a code serving a purpose other than secrecy.

Yep.  For additional clarity, according to the CFI Notebook -

Transponders came about during World War II when the British developed a transceiver which was capable of identifying friendly aircraft

This system was called "Parrot" which led to terms like "squawk your parrot" (turn on your transponder), and "strangle your parrot" (turn your transponder off)

The U.S. adopted this same system and instead called it "Identification of Friend or Foe," or IFF, a term still utilized by the military today

Like the term IFF making it to modern day operations, squawk stuck around too which is why we are assigned a squawk code to allow ATC to see where we are

just why? can't they just say transponder?

I can understand if it was pilot slang, but I’m surprised to see the FAA include the term in a chart supplement.  I wonder if it’s a regional thing i.e. referring to a transponder as a parrot is more common in Alaska or northern Canada, than in the southern CONUS.

@AadirajAnil because it ties back to NATO code words. Will let you draw your own conclusions about how some of them got thought up. https://en.wikipedia.org/wiki/Multiservice_tactical_brevity_code. Is a valid question if military terms from quite a long list should be showing up this way.

@Romeo_4808N apparently Parrot was originally British.  Certainly WWII UK military projects used codenames like that.

Added clarity was provided regarding historical development and term usage.  The term parrot is apparently ubiquitous...


text:
What causes stall buffeting?
From other answers I've gathered that stall occurs when the air flow separates from the wing surface. And also that this starts at the back of the wing and progresses forward as AOA increases.
Is this process not uniform? What causes the buffeting just under the stall AOA? Is it simply the turbulence behind the point of separation?
Also, what factors, such as speed, altitude or air density affect the amount of buffeting?

This may also have to do with the "twist" in the wing, the chord angle (AoA) closer to the root of the wing is different than the chord angle near the tips on some aircraft (like a Cessna 172). This means as the stall progresses, the root of the wing stalls first, and the tips last, I was told this is for aileron effectiveness during a stall. This could contribute to the buffet as basically the points of lift move further out as the stall progresses.

Not all stalls start from the trailing edge and progresses forward. In general, three types of stall are described:

Trailing edge stall- This is the preferred stall characteristic; The turbulent separation point moves forward from the trailing edge with increasing angle of attack. usually found in airfoil sections with thickness ratios 0.15 and greater.
Leading edge stall- The flow separates abruptly from the leading edge without subsequent reattachment; usually found in airfoils with thickness ratios between 0.09 and 0.15.
Thin airfoil stall- Found in airfoils with small thickness (< 0.09), the separation occurs at the leading edge and the flow reattaches at a point which then moves progressively rearward with increase in angle of attack.

Buffet is a kind of vibration caused by aerodynamic excitation, usually associated with separated (or turbulent) airflow. As the aircraft approaches stall, the airflow over the wing becomes turbulent and if it flows across the horizontal stabilizer, buffeting may occur.
Whether low speed (stall) buffet happens or not depends on the aircraft characteristics; for example, the stall starts from the root in case of straight wings and the stabilizer is affected by the turbulent airflow before the outer wing stalls- this can be used by the pilot to take corrective action (as @Ron Beyer points out in his comments). In case of swept wing aircraft, the stall progresses the other way around- from tips to rot and it will be difficult for the pilot to use buffet in any real sense.
This buffeting can act as a warning for the pilot that the aircraft is approaching stall and he/she has to take corrective action. In aircraft that do not show this behavior, some warning cues, like stick shaker are sometimes incorporated in order to warn the pilot.
As density altitude increases, the angle of attack required to produce turbulence at the top of the wing (stall angle) decreases till a point is reached that the high speed buffet (Mach buffet, due to supersonic airflow) and the stall buffet (as already explained) converge. This point is called the coffin corner.

"CoffinCornerU2" by Department of Defense - AF (C)-1-1, Flight Manual, Models U-2C and U-2F aircraft. Page 6-11. Licensed under Public Domain via Wikipedia.
From FAA Handbook FAA-H-8083-3A:

An airplane’s indicated airspeed decreases in relation to true airspeed as altitude increases. As the indicated airspeed decreases with altitude, it progressively merges with the low speed buffet boundary where prestall buffet occurs for the airplane at a load factor of 1.0 G. The point where the high speed Mach indicated airspeed and low speed buffet boundary indicated airspeed merge is the airplane’s absolute or aerodynamic ceiling. ... the airplane can neither be made to go faster without activating the design stick puller at Mach limit nor can it be made to go slower without activating the stick shaker or stick pusher. This critical area of the airplane’s flight envelope is known as “coffin corner.

Wow, that leading edge stall sounds kind of nasty. Can you give an example of an aircraft that exhibits that type of stall behavior? And on the thin airfoil stall, when the flow reattaches does that shift center of pressure backward causing a nose down?

@TomMcW You're correct that in case of thin airfoil stall, there is an increase in the nose down pitching moment as the separation bubble envelopes more of the the airfoil upper surface. For Reynolds number range of normal operating conditions, leading edge stall is found in some helicopter rotors.

@aeroalias I liked the ref. from the FAA handbook but you seem to have confused turbulence and turbulent flow with stall [...the angle of attack required to produce turbulence at the top of the wing (stall angle)...]. The flow before detaching can be either laminar or turbulent, this is a state of the flow. I mean that in cruise attitude, you have a small laminar part near leading edge and then the flow transitions to turbulent being fully attached to the wing.

This article states it pretty well (better than I can word it).

When the angle of attack (AOA) of the wing increases, the point where
  the airflow separates will move forward and the streamlined airflow
  will become turbulent and separate from the wing. This turbulent wake
  then meets the aft fuselage and tail section of the aircraft. This
  will be felt by the occupants of the aircraft as a rumble or buffet.
  Not all aircraft have a pronounced buffet, this depends on the size
  and location of elevator.

Interestingly enough you can also induce a stall (and first high speed buffeting) by gong too high and too fast while trying to maintain level flight which will cause the center of lift to move aft along the wing. Basically your stall speed and your critical mach number eventually converge this is known as the coffin corner. There is a nice discussion on it here.


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What do pilots do to prevent DVT?
I was reading an article on deep vein thrombosis in air travel. It seems that the problem is more prevalent than one would think. A great deal of effort goes into preventing planes from crashing but people are many times more likely to die from pulmonary embolism than a plane crash.
I'm wondering what steps have been taken to mitigate the health risks for pilots who spend many more hours sitting in a cramped seat at 8,000 ft of cabin altitude than most passengers. The most common advice for travelers is to do exercises to keep blood flowing and get up and move around occasionally. Is this practical for pilots? It doesn't seem like there is enough leg room to do exercises, not to mention that there are rudder pedals that could cause problems if you push them at the wrong time. If one of the pilots gets up the other pilot is often required to wear his oxygen mask until the first pilot returns. This would tend to make the pilots keep their cockpit excursions to an absolute minimum.
Do most pilots wear pressure stockings? That is another way to help prevent DVT. Is this a priority among the airlines and pilots themselves?

I retired in 1999, so what I say is only of possible historical interest. In my day (damn, that sounds like I'm really old, damn, I am really old) we didn't worry about DVT, and it was never a problem with me or any pilot I knew of. I typically left the seat to strech or use the toilet every hour or so, and I always tried to walk the cabin at least once on long flights (747 so most were long). We had no requirement to wear oxygen masks, but these were three man crews and we did observe the rule that only one cockpit crew member could be out of the cockpit at a time.

Deep vein thrombosis (DVT) or Traveler’s Thrombosis occurs when blood in a vein (most often in lower extremities) becomes stagnant and then forms clot. If you think about it, the pilots are at less risk compared to passengers in this matter. FAA advices certain steps to prevent DVT, like,

Increasing leg muscle activity during long periods of sitting improves blood flow in the legs. This may include walking around the cabin or exercising your lower legs and ankles while seated.

Drinking adequate fluids, and avoiding alcohol and caffeine, may also help by preventing dehydration.

Some recommend taking short naps, instead of long ones, to avoid prolonged
inactivity.

It would be much easier for the pilots to do these things compared to say, passengers.

Pilots usually have more room in the cockpit compared to passengers in cabin.

In long haul flights, there is usually a standby crew member who is rotated so that the pilot could get some movement and rest.

It is certainly practical for the pilot to get up and stretch his/her legs during flight. It is not as if they are flying the aircraft hands-on every second for the entire flight. In any case, the flying duties could be alternated between the two flight crew without any problem.

It is not unknown for pilots to take short naps in the cockpit

Studies indicate that the DVT is more prevalent among the passengers than the pilots. According to Deep vein thrombosis in commercial pilot:

10 percent of air travel passengers older than 50 years develop symptomless DVT during prolonged flights. DVT among air travellers has been documented, but is rare among pilots flying commercial aircraft.

Also, it seems (some pilots, at least) do wear flight socks.

It seems that the pilots don't take the wearing of oxygen mask seriously.

It is not unknown for pilots to take short naps in the cockpit - This sounds a bit scary to me, and the way you worded it seems to imply that's it's frowned upon. Perhaps this should be its own question, but is this legal according to FAA or other regulations, or "normal"?

@Steve We already have a question on that

You got me to wondering why dvt is so rare in pilots compared to passengers when both are sitting for the same length of time. Did some reading and it comes down to this: risk factors. Many people who develop dvt have an underlying health condition, most of which would probably keep someone from passing a medical. Another big risk factor is women on oral contraceptives or hormone therapy. This could only apply to the approximately 5% of pilots who are female.

@TomMcW Another point is that pilots are usually healthier than the general (flying) population. Symptoms of DVT will mean that the pilots cannot fly till the issue is sorted out.

Oddly enough, according to this article athletes are at a greater risk of dvt.


text:
Is there always a stall if you exceed a specific angle of attack?
So lets consider that the stall angle (=Cl max) of a B747 is at 16° (in clean configuration). Does this mean, that, at whatever speed you are flying (i.e. 500 knots), you would stall if you go on a climb angle of more than 16°? So there is no need to always reduce the speed to the stall speed (which might lie at around 150 knots...).
I am just wondering, since, if you fly in the microsoft flight simulator with a big jet, you can have an angle of attack of 30° and more, and not stall until you get to the stall speed.

related: http://aviation.stackexchange.com/questions/2903
http://aviation.stackexchange.com/questions/6366

I think you are confusing Angle of Attack with pitch angle relative to the horizon.

AoA is the angle between the airstream and the wing (roughly, the vertical angle between the way the plane's pointing and the way it's moving). If you're climbing, your AoA is less than your pitch.

I am sure this is already explained somewhere around here, with pretty pictures, but the related question finder is not good enough to find it. And I can't find it with google either.

this is by definition: "a stall occurs then the wing exceeds the critical angle of attack"

Is there always a stall if you exceed a specific angle of attack?

Yes, stall depends only on angle of attack. However

Does this mean, that, at whatever speed you are flying (i.e. 500 knots), you would stall if you go on a climb angle of more than 16°?

No. Climb angle and angle of attack are completely different things.

This image from How It Flies shows the four different angles involved. Pitch is the angle between aircraft floor and horizontal, wing incidence is angle between aircraft floor and wing¹, angle of climb is angle between direction of flight (a.k.a “flight path” or “relative wind”) and horizontal and finally angle of attack is angle between direction of flight and wing.
The image shows that angle of attack + angle of climb = pitch + wing incidence.
Up to stall, lift depends approximately linearly on angle of attack and square of speed (and on air density). In straight flight the forces on the aircraft need to be balanced, so angle of attack will be such that they are. If you increase pitch, the angle of attack will increase, which will cause unbalanced force, which will cause upward acceleration and that will increase the climb angle at the expense of the angle of attack again.
So if you go on a climb more than 16°, the angle of attack will not significantly differ from what it is when you fly level at the same speed.

I am just wondering, since, if you fly in the microsoft flight simulator with a big jet, you can have an angle of attack of 30° and more, and not stall until you get to the stall speed.

No, you can't. You, however, can climb at 30° or more, for a while before you run out of speed. Which at low altitude is actually quite long; the jet engines are designed to have enough power at high altitudes where air is much thinner and to allow taking off when one engine fails late in the take-off roll. Therefore low with all engines operating at full power you have quite a bit of extra thrust available.
Also note, that stall does not mean loss of all lift. You only loose part of it. A significant part, but not all. Stalled aircraft is still controllable (though ailerons effect is reversed) and some aircraft (though this would be fighters, not airliners like 747) may even have enough lift and thrust to maintain altitude when stalled.

¹ Specifically, the zero-lift line of the wing. This coincides with the chord of symmetric wings, but cambered wings have it tilted up.

Would it be correct to say that the angle of attack is the angle between the wing and the relative wind?

I agree with Terry - 'relative wind' is the usual term to describe what you are calling 'flight path'. Both are jargon, to a degree, so I dunno if it matters much.

"No you cant"? Well.. you certainly can with an SU27. In fact, you can fly with an angle of attack of 108 degrees (that's angle of attack, not angle of climb)

@slebetman: No, you can't. The Su-27 is deeply stalled when doing that. It can, however, still maintain horizontal flight, because it has enough thrust; an example of what I mention in the last paragraph.

Short answer: No.
Long answer: The stall angle of attack varies with speed, altitude, Mach number and the rate of angle of attack increase, as discussed here and here. Since the lift curve slope of a wing does not change with the pitch rate, a high pitch rate will indeed increase the stall AoA by up to 50%.
Speed and altitude effects are expressed in the Reynolds number, and this will also shift the AoA up by several degrees when increased from, say,  200,000 to 5,000,000. The influence of the Mach number will really manifest itself above Mach 0.5, but if the leading edge radius is small, it can already make a difference of several degrees between incompressible conditions and Mach 0.3. Stall at higher Mach numbers is more complex, because before lift drops, the wing will experience increasing buffeting, which by itself will limit the operational AoA.
Next, pitch angle and angle of attack are not the same, but they differ by the flight path angle and the wind angle of attack, which is nonzero if you fly in an up- or downdraft. This is discussed in detail here.
If your engine or airspeed allows, you can fly a full loop without ever stalling the airplane.

would you mind expounding on your conclusion that the critical angle of attack varies as you described? The documentation you cite only states that the maximum CL achieved by the wing varies with the above-mentioned factors; the actual angle of attack at the point of stall does not appear to have been measured during these experiements. The CL conclusion is a very interesting one indeed, which raises a few questions about the way we teach VG diagrams to pilots, but my reading of it suggests that this might be more of an artifact of wing or experiment design or the nature of fluid dynamics.

It is worthwhile to note that the study mentions two other experiments that did not produce the same results - i will freely admit that I did not dig into those references due to lack of time, so i'm not familiar with their full conclusions. Also, a properly flown loop should have a constant load factor throughout, meaning that at no point during the maneuver should the aircraft enter a stall.

@habu: The lift curve slope is unchanged, and the higher $c_L$ with higher pitch rate does indeed include a higher stall angle of attack. Note that when a wing stalls, recovery is also delayed with higher pitch rates. The mechanism is explained in the linked answer. Regarding the loop: When properly flown, the load factor should be 2 g less at the top - constant curvature at constant speed would create a constant load factor, and gravity, which changes with the cosine of the pitch angle, must be added to that. Realistically, speed is also less at the top, so centrifugal forces change as well.

the second answer provides a good explanation of why, under certain circumstances, an aircraft might not immediately display expected stall behavior until after the boundary layer has had a chance to catch up with the aircraft's new attitude (side note: anyone else picturing Wile E. Coyote reading that?), but it does not change the fact that once things "settle" the aircraft will, in fact, enter a stall should it find itself at an AoA higher than the critical angle of attack.

@habu: Yes, that is correct. But sometimes this short moment of unstalled extra lift can make all the difference. Don't count on static conditions to apply everywhere, especially when dimensioning wing spars and the like!

The delayed flow separation is what makes very-high AoA maneuvers possible, and, to your point marks the correct answer to OP's question as no, but I wonder if it might not be worth explicitly pointing out that each wing has a critical AoA that can only be exceeded in some very, very specific circumstances and only successfully "cheated" if the aircraft has the kind of power-(or thrust)-to-weight ratio only found on modern fighters and high-performance aerobatics aircraft.

@habu: You will equally be able to see this delayed stall on gliders, no need for any thrust here! And please don't neglect the influence of Reynolds number and Mach number: The stall AoA is changed by them a lot. There is nothing like one, fixed, immutable stall AoA.

you are, of course, correct about loops. I was thinking of constant radius throughout the maneuver and somehow ended up with load factor. To state the obvious, a slower-speed turn (which would be the case at the top of the loop) will require a lower load-factor to achieve the same radius as a higher-speed one, hence the lower g-loading at the top of the loop.

interesting. I was unaware that gliders can display that much maneuverability, even the aerobatic ones. But just to clarify, when I say "cheating" the crit. AoA, I am refering to maneuvers such as Pugachev's Cobra and Thrust Vectoring loops, though to your point, that is likely more a result of continued control authority rather than thrust +1 for getting me to think about a few things I hadn't revisited in years, btw.

@habu: Pugachev's Cobra maneuver happens long after the wing has stalled, and is only possible by massive thrust and the careful post-stall design made at TsAGI. Only in the initial pitchup phase will the pitchup-rate effect manifest itself. And in gliders it can be as much the wind (thermals!) as the pilot which will change AoA quickly. If you have ever flown through a strong thermal at moderate speed, you know what I mean.

For a given wing configuration eg leading/trailing flap, sweep etc, the stall will occur at the same AoA in incompressible flow (low speed, low alt flight) - that's assuming you can clearly define the stall as some fighter aircraft don't have a sudden classical lift break, rather their stall might be defined by rapid drag rise, controllability, handling issues.
For compressible flow, ie flight at high Mach number, the stall AoA will reduce: Stall AoA at 300KCAS/sea-level is greater than the stall AoA at 30,000ft/300KCAS.
Two effects at play here... Compressibility and Viscosity. The effect of compressibility is the predominant one.
Viscosity (Reynolds number). For a given wing design and configuration, as you go up in altitude, the density of the air decreases, while viscosity increases with lower temp. This has a small effect on Reynolds Number.
Compressibility: energy lost in compressing the air is significant at higher mach, which is why you see lower AoA for a given defined stall.
Incidentally, buffet onset is not always a defining attribute of the stall as some jet fighters will experience buffet at very low AoA eg 6-7 degrees, well before the defined stall.


text:
What is a “HIDE” system on F/A-18?
On the ATC recording from this video a Blue Angels aircraft has declared emergency. When ATC asks for information about the problem the pilot responds, “one of our hide systems is malfunctioned and it prevents us from extending our gear normally. So we have to emergency extend the gear which forces us to take an arrested landing if able.”
What is a “hide” system? If that is in fact what they’re saying. That’s what the video transcribes it as and it could be wrong. Also, why would a failure cause emergency gear extension? And why does emergency extension force an arrested landing?

That last question maybe should be split off into a separate question. ??

"Hyd" is slang for hydraulics. The landing gear is powered by one of the hydraulic systems, so if that system was down, the pilot wouldn't be able to extend the gear normally. The brakes are also powered by hydraulics—hence the need for an arrested landing.

Correct.  She’s referring either to HYD1 or HYD2, not ‘hide’.


text:
In what cases does it make sense to buy a plane before you begin pilot training?
I'm halfway through a 10-year plan to pay for pilot training and buy my own plane (or a share of one).  When I was introduced to flying by a friend, he said if he had the chance to do it over again, he would have saved up and bought a plane before he started instruction.
The benefits he mentioned:

Learn in the plane you'll be flying.
Avoid "throwing away" rent money.

What I've seen in most cases, though, is that most people get their license before getting a plane.
Thus my question: when does it make sense to buy a plane before training for your PPL?

We would assume you mean an aircraft commonly used as trainers, perhaps a Cessna 172 or Piper Archer? If you bought a Baron twin, (I assume) you could not take your initial training in it.

Yes, that's a valid point.  I'd be purchasing a 172 or 152, or a similar "starter" plane.

@CGCampbell Theoretically, you can get trained in any plane. Practically, it is not very feasible.

I made a spreadsheet to figure out the costs associated with owning my own vs. renting while training. It came out that I needed to fly 100 hours a year for it to be worth owning my own plane vs. renting, but I lived in a place with a great club (KMYF) that had incredible rental rates.  Aircraft prices also tend to be somewhat steady in the 172/Cherokee market, so you may be able to fly one for a couple hundred hours and then sell it after you're done training and almost "fly for free." The risk you're taking is having to pay a major maintenance expense before you built up your reserve.

@Canuk, did you take into account the resale value of the plane you would theoritically buy, or did you count the entire cost of the plane as a sunk cost?

@DanielAllenLangdon I took into the account the resale value, that is what really makes it work. You're just taking a gamble on not having a major maintenance expense while you own it (like a top overhaul, new propeller, etc), that if you held on to it for longer would amortize better over the total ownership time, but in a short time can eat up the savings you're expecting. Also, you have to think about how easy it is to buy and sell (you should always pay for a quality pre-buy inspection, and if it takes a couple of these to find a good plane, that can be a couple thousand.

Take a look at this video which has a cost analysis of buying/owning a small airplane: https://www.youtube.com/watch?v=qFIjWVCUBHk. One problem with owning a C152 that it can literally just fly only two people ( roughtly 180lbs each ) with no baggage. If you want anything more than this for the future, you should consider a larger plane like C172.

@Canuk Would you be willing to share your spreadsheet? I'm also new to the topic and am very keen to learn as much as I can to make an educated decision about this.

@沖原ハーベスト I'd be happy to share my spreadsheet: https://docs.google.com/spreadsheets/d/1SGMs1JxducMfHiwSbbAyJVVGBnbbT97YUxJ7pw8GOnI/edit?usp=sharing Just change any of the numbers in bold blue text to update the calculations. It's definitely not the final word in the analysis, but it helps you think about all the fixed and variable costs.

@Canuk Awesome, thanks mate! I'll check your spreadsheet out later tonight.

"I'm halfway through a 10-year plan to pay for pilot training and buy my own plane (or a share of one)."  Is that 1 year for the license, and then 9 more years to buy one?  I bought a C150 with 2 coworkers, just $5K each. We all got our licenses in it in about a year. About a year after I was licensed, I bought a C177B, an kept in the 150 long enough for my wife to get her license. Having our own plane to learn meant we were not dependent on the flying school having a plane available, and once cleared to solo we could do that when we wanted; and it was nice having something steady to learn in.

I will mention some considerations that were not mentioned above. First of all, it does make sense to buy a plane for training, and it can save you a lot of money on rent but you need to be aware of what you are doing. The positive side is that airplanes do not depreciate as fast as most assets of their kind (it is not unheard of being able to sell an airplane for practically the same amount as you bought it several years ago). However, consider that:

Usually an airplane you want to train in (something sturdy and easy to control, like a C-150) is not an airplane you would like to fly most of the time (traveling in a 150 is not a lot of fun, now a twin Comanche is a different story...).
Insurance costs for a student pilot (even with various restrictions) can nearly negate the advantage of not having to rent.

So, if you would like to buy an airplane to mostly train (and have some fun occasionally) and then sell and buy a 'travel' (or aerobatic) airplane, it can save you money. It is better to get your private first, however, so you can concentrate on initial training (which is a handful) without worrying about the 'pleasures' of plane ownership.

Thanks for the input--my goal would be to get a 172, or even fractional on a 182.  Would it make sense from a training point to use those types of planes?

A 172 makes a fine trainer. A 182 would do in a pinch but they're a lot more powerful and the learning curve could be problematic. Insurance would probably increase correspondingly.

I would also think twice about a partnership: they are a lot harder to get out of in case you need to. You would also have to think about how to proportion expenses such as annuals, maintenance, etc among the partners (would it depend on how much one flies, for example?)

@alexsh partnerships are definitely harder to get out of, but they are great when they work! I went into it with the mindset that I was in for life! We proportion expenses by "renting the airplane to ourselves" and pro-rate time-limited parts and put it into an account (for example, $20/hour for engine maintenance reserve, $5/hour for propeller, etc.) and then we all pay our share of fixed expenses (these are expenses that are if there if fly or not - such as annual inspection, tie down, insurance)

My big point against it is that you don't know what plane you'd want to buy. When I started training, I had my heart set on owning a DA40. Wanted one more than anything. 300 hours later and some horribly uncomfortable cross countries in that thing, I'm much more comfortable and happy with my 172.

@Canuk Agreed, this is a very fair way of proportioning the expenses and partnerships are great if your partners are reliable. I was only cautioning to weigh all the risks first.

@Chris Most people prefer low wing planes for almost no other reason than 'they look sexy' but it is nice to stand under the wing in a fly-in when the sun is out or when it is raining. Also, walking on the wing to get into the plane does not do the skin and the ribs any service. So C172>D40 in my book :)

There are two assumptions in your questions which could be addressed.
First, learning in the plane you'll be flying: it might also be useful to learn to adapt to different planes. Each plane is a bit different to control and not everything on the plane is standard across manufacturers. You might be better off starting to learn how to adapt your flying to the machine instead of locking yourself into a particular model.
Second, rent money isn't really "thrown away". You're paying for the convenience of not owning which is to not have to think about issues like maintenance for example. Let's you focus on the joys of flying.
On the other hand, it makes sense to buy a plane before learning how to fly if:

you're 100% committed to flying
you worked out all the costs (money, time, your energy, etc.)
you're able to go up the learning curve of how to fly + be an owner at the same time

Also, it's worth remembering that an airplane is an asset that depreciates over time.

I'm not sure they depreciate all that much.  It seems like most used, old (pre-80s) training planes these days are actually rising in value because new planes are so ridiculously expensive and fewer are being made.  Low supply, high demand...  If you buy the right plane, depreciation isn't really a consideration.  Now, loan interest...that's another question.

Regarding depreciation of airplanes, this question is sort of related: http://aviation.stackexchange.com/q/3370/65

If I were you I'd only buy an airplane once I'd successfully got my license and flown enough to know what you want to own long-term. Once you know more about it you can make an informed decision. Also, you will be able to judge whether an airplane is worth buying, or whether you'll be inheriting a load of expensive problems.
Owning an airplane is very expensive, with a lot of up-front costs. It only makes sense over renting if you fly a lot, and even then over time.
By all means start saving, but wait.

To address your worry of me buying a klunker: I'd have my pilot friend with the experience help me through the process to pick a solid plane.

This is an important consideration but would you have enough experience of deciding that this is something that you would like flying. The more you fly the more your tastes will change. A Citabria, for example, feels very uncomfortable to a fresh pilot but it is a fun plane to fly once you get proficient in it.

The first thing I would do is put on paper for your benefit what the mission is.  Are you seeking a pilot career, or just want to fly for recreational purposes?  How many people will you be carrying on a regular basis? How far away are the destinations?  (Like from where you live to where your wife wants to go...  New York City to the Cape Cod area, in my case) and what kind of plane will carry the load you intend on carrying (kid stuff like strollers, playpens, and other...).  When all that is done, it will come close to defining the plane that is best for your needs.
Now the big question:  Is that the plane you want to train in?  Is insurance affordable for a zero time student?  Can you find a CFI to instruct in that plane?  After you slam it on the ground for say 100 crash-and-go landings as you come up the learning curve, is that the plane you want to carry your family in? How difficult is it to find a flight instructor for that airplane?  If yes, do it.
Second big question, as mentioned above, how many hours per year do you anticipate flying?  It is pretty easy to calculate the annual flying bill if you are a renter.  Ownership will most likely be MORE expensive than that, because all of the fixed expenses are paid by you and not diversified among other renters.  If you have a bad annual inspection, as but one example: the renter can just walk away and find another plane/flight school.  The owner must pony up the repair costs or he is left with an unairworthy aircraft worth a fraction of the value in a sale.  One way or another you will pay for the repairs to get the plane back in annual.
So renting during training may be cheaper and with less downside risk.  It will also allow you to clarify in your own mind what you want out of this flying thing, without the burden of ownership.  Owning brings the absolute freedom and joy of owning your own plane ... as well as the financial obligations of ownership.
Again, as noted above, most people use 100 hours of flying annually as the breakpoint between renting being better, and owning being better - but this will differ with each individual and each plane.  I wish you luck with the decision, and also with your training.  Come on up, the air is smooth and cool up here!

I considered buying an airplane, I even came close but backed away because the particular airplane had some engine issues. In retrospect, it might have been cheaper to buy a plane at the start, but now I'm glad I didn't, primarily because the 150 I was looking at would not be a satisfying long-term airplane for my purposes.
There is an advantage not mentioned in the previous answers, namely scheduling. Your airplane is always available (barring maintenance issues or instructor availability issues). However, the disadvantages, I think, outweigh the advantages.
If cost is one of the major factors for you, consider joining a flying club that is geared toward training. That's what I did. After an initiation fee, wet rental of our club 150s runs between 50 and 55 dollars (US) per hour. An added benefit is the social aspect of the club, it tends to reinforce the effort to finish getting your ticket.

One more scenario to consider: You get a deal "too good to refuse", and know it really is a good deal and you're not buying a lemon (maybe you can get a preferential selection from an auction of a bankrupt company, or from the estate of a deceased friend or relative).
That could potentially save you a bundle, more than the maintenance, taxes, and insurance you'd have to pay before you'd otherwise be willing and able to purchase an aircraft.

Of course there's also added risks involved, quite apart from the monetary side of it ending up more expensive than renting and buying later.
And that added risk is that you may for whatever reason end up having to abandon your dream of attaining your license and are now stuck with that aircraft that you may or may not be able to sell without a serious loss.
Think you get into a major car crash and lose an eye or leg, meaning you can't pass your medical. Or you get a heart condition with the same result. Maybe your financial situation becomes such (employer goes bankrupt, causing you to lose a lot of money, happens more often than you think) that you can't continue to pay for flying (if it's a choice of paying your aircraft dream or the rent or mortgage on your house, or to put food on the table...).

So weigh the risks carefully, don't get all glassy eyed seeing that glossy aircraft for sale at an airshow and sign for the thing before you consider what's in it for the future for you.

One thing not yet mentioned I think is the option to set up a small company and register the aircraft to that, then using that company to rent it out to the flight school you're taking lessons from (or to a local flying club). That way the aircraft generates a bit of income, which you can then use to pay for its maintenance and insurance, with who knows maybe some left over to help pay for your flying lessons as well.

..option to set up a small company ..then ..rent it out - very interesting idea concerning ownership at the macro level, beyond just learning to fly.


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What are common downsides to leasing an aircraft to a flying club?
I plan on owning my own plane in the coming years and using it to get my PPL.  I've recently been turned on to leaseback with flying clubs.  The pros seem to heavily outweigh the cons, but I always wonder.  What are the common (and uncommon) downsides to employing a leaseback with your own airplane?

Related Questions: Buying an aircraft in which you will do your training and buying an aircraft in which you will give instruction

A leaseback can be advantageous, especially when you use the aircraft for your own flight training and travel.  But there are some things you need to watch out for:

Other people will be using your aircraft - whether people admit it or not, nobody will take care of the plane as well as you do. If you think you might take issue with trash in the cockpit, a scratch on the panel, or a tear in the seat, you might want to give this a second thought. In my experience, flying clubs seem to have pilots that take better care of the aircraft, since membership is controlled.
You'll have to schedule your flights - just like everyone else (though some concessions are usually made for the owner). The bottom line is, you won't be able to just get up and go fly somewhere at a moment's notice anymore.
You have to play by someone else's maintenance rules - While you have to comply with FARs  in any case, the lessee typically will have stipulations that they (or their designee) will perform any required maintenance on your behalf and your say in the matter will be limited. Of course, you still have the honor of paying for any maintenance performed (typically at little or no discount).
Your capital is tied up - This can be a good or bad thing. It's good in the sense that aircraft tend to be a good hedge against inflation risk. It's bad because you're precluded from using the money on something else. This is one of the main reasons that flight schools/clubs LOVE leasebacks.
If you're looking to make money... it won't happen - most leasebacks only help offset the expense of operating the aircraft. If you're looking for a return on your investment, better to look somewhere else. Do it only to reduce the cost of ownership on something you want anyway.
Finally, YOU take on the financial risk of the aircraft - in most leaseback situations, you are reimbursed for any use, but are still responsible for any finance and indirect (and sometimes direct) maintenance costs. These have to be paid, whether the aircraft is flying or not. And if business starts to slow down... well, I'll give you a hint: it's not the flying club that has to pay to keep your plane airworthy.  This is the main other reason flight schools/clubs LOVE leasebacks.

How long do the leases typically last?

I think 1-2 years is typical, but it's whatever you're able to negotiate. You can also have a termination clause added that allows you or the flying club to cancel the arrangement, with proper notice.

Another item to bear in mind is insurance: An aircraft on leaseback is usually required to have commercial insurance (since it's used for rentals and the insurance company doesn't know who the pilots flying it will be). The owner is often responsible for paying for that insurance, and the premiums are significantly higher than non-commercial (personal-use) aviation policies.

Another potential disadvantage: the aircraft is going to rapidly clock up flying hours, reducing its potential resale value and increasing fatigue and other wear and tear. This might be offset by the income from the lease, but do the math carefully...

@GarrisonNeely my leaseback is month-to-month, with 30 days notice of termination for them to cover all outstanding reservations on the plane. All the clubs I looked were this way.

Along with other answers, here are my main points. I purchased a 2012 172 about 6 months ago, and it's been on leaseback for about 3.
1) Be seriously OK with some light cosmetic damage, and protect against it as best you can. People touch screens, and people sit on pens after writing down their clearances. Get some seat covers, screen protectors if it's a glass cockpit, etc.
2) Talk with your club before making modifications. It's your plane, but certain mods (throwing a STOL kit on it, painting it bright pink, etc) may reduce or increase the hours/month it flies.
3) Define what type of training it'll be used for. For example, my plane has WAAS, so I requested that most of the training in it is IFR and CPL students. This is a huge saver when it comes to wear and tear, but it flies less than the planes used for primary instruction.
4) They'll try and take you to the poor house on maintenance, so shop around. One club I looked at wanted \$125 / hour plus 20% on top of of all parts ordered. Another club 10 miles away, where my plane currently is, is costing me \$80 / hour.
5) Take the wheel pants off. They're fiberglass and they will be stepped on, cracked, kicked, etc. Plus, with the pants off, it's much easier to inspect the tires and see any defects before they turn into a problem.
6) Don't expect to make money off this, period. Nobody's ever gotten rich leasing back a 172, but if you're careful it's generally enough to cover the vast majority of your day-to-day expenses. Just remember to set aside money each month for the inevitable \$30,000 engine rebuild or \$10,000 ADS-B install.


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Can wind shear conditions be identified visually?
Without relying on winds aloft or LLWS data, can pilots identify wind shear conditions visually, by watching clouds or otherwise?

We don't have enough weather questions up in here!

Can you see wind shear?  Nope, but you can sometimes see indications of it.  According to Airbus, windshear is usually associated with the following weather situations (photos found on Google images by me and are clickable to take you to the source):

Jet streams

Mountain waves

Frontal surfaces

Thunderstorms and convective clouds (and I added virga here too)

Microbursts.

Avoid these at all cost!  Actually, that's the easy part.  The windshear without the visible signs is more the issue, and csatlos's answer does a good job of telling you what to look for during flight (especially takeoff and landing when you are low and slow).

Clouds with flat tops or bottoms (anvil shapes) can indicate wind shear. Fronts are usually accompanied by wind direction and speed changes which can easily be seen in the clouds as the front approaches.
Smoke stacks can provide an indication of wind shear if smoke changes direction or shape as it rises.

Another good trick is looking at two wind socks on the field at different heights (for example, one in a wind circle on the ground, and another on top of a hangar) -- If the wind socks can't agree on the wind direction there's a good chance you'll encounter wind shear somewhere between the top of the hangar and the ground.

@voretaq7 answer?

Good photos, but there are many indirect wind indicators that can affect aircraft especially when in close proximity to the ground.
One I experienced between Whitehorse and anchorage at about FL330 was a 9° temperature rise. A couple minutes later I flew into sever turbulence for about 30 seconds. The turbulence stopped and the temperature went back down. I was above an overcast and clear above but I could see through a small hole in the clouds some mountain tops. I check a chart and there was a mountain about 18 thousand feet tall. I figured that the cause was mechanical lifting of the jet stream over the mountains and I few through the burble on the backside of the mountain which cased the temperature to rise. So be very careful around mountains, things can happen with or without clouds as show in another comment.
Other things to look for that a lot of pilots may not be aware of is to learn the surroundings of the airports that you intend on flying into even your home base. Look for major features that could have an affect on wind. For example Hot Springs, VA has a mountain top airport and the wind blows upward and over the far end of the runway and then down to the runway a few thousand feet toward to departure end. What effect the wind has on an airplane as it enters the null area of little wind is that there is little acceleration on the airspeed indicator. The airspeed indicator also indicates the effect of the wind over your wings which can be very interesting.
If you are close to large bodies of water and the airport is within a couple of mile from the water there can be very strong changes in the wind direction. I was on final at 3000 ft. with a strong wind from the right with a crab that caused me to view the runway through my side window. As I descended to within about 600 ft. I got into lake effect wind and ended up turning the airplane about 60° left to keep lined up with the runway.
Look for quarries and undulating land features that can indicate airflow. You cannot see the air but you can certainly see the land features that will give you a pretty good idea what to expect. Just this last weekend a corporate jet, after making a go around in Aspen tried to land on the second attempt and crashed. The wind was from the northwest 15 gusting to 25 kts. Aspen has a large mountain just to the west side of the runway and the pilot was attempted a down hill landing with the far end of the runway 200 ft. lower than the approach end which is at the max allowable of 2%. Aspen id 7800' AGL.
There are a lot of wind gotcha's out there, this is a good topic keep them coming guys.

A combination or one or more of the following conditions may indicate wind shear is present:

Indicated airspeed variations in excess of 15 knots
Groundspeed variations (decreasing head wind or increasing tail wind, or a shift from head wind to tail wind)
Vertical-speed excursions of 500 fpm or more
Pitch attitude excursions of five degrees or more
Glideslope deviation of one dot or more
Heading variations of 10 degrees or more
Unusual autothrottle activity or throttle lever position

These are visual indications in the sense that you're looking at the way the aircraft is performing versus out the window for cues from the environment.


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What happened to the 737's cockpit skylights?
Older-model 737s had very distinctive set of upwards-facing windows above the main, forwards-facing cockpit windows; not unlike those you'd find on MD-80-series airliners and on 727s.
These windows appear to also be present on early-model NGs (or retrofitted classics; I have a hard time telling, and absent on later-model classics; specifically ones with high-bypass engines).

(Photo likely by Maor X on Wikimedia Commons)
On later-model NGs and the MAX, however, these windows are gone:

(Photo by Jpedreira on Wikimedia Commons)
Why would these windows, which are arguably useful in giving pilots a better vertical field-of-view, be removed? Has their usefulness in finding nearby air traffic been superseded by TCAS and ADS-B? Even then, why remove the windows when they act as (an extremely reliable, albeit less-precise) redundant system?


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What is a Second Officer?
I've seen the position of Second Officer being advertised for some short-haul airlines, but I don't entirely understand what roles and responsibilities they have on the flight deck.
I know a second officer exists on long-haul flight, which allows for crew to take rest breaks through the duration of the flight. So what do they do on short-haul flights? Are they still under line training?

Definition
A second officer (SO) is third in line of command on an airplane. The purpose of a second officer is:

a Second Officer is used on international or long haul flights where
  more than two crew are required to allow for adequate crew rest
  periods.

I have never seen anyone besides a captain and first officer on a short-haul flight. Such flights normally don't even require either the captain or first officer to take a break to rest.
Duties
Second officers are qualified pilots and also type-rated for the airplane they are on, similar to the captain and first officer, but only with lesser experience. I do not know the exact career path for them, but most probably they are promoted to become first officers. This is same as first officers are promoted to become captains.
Jobs
There are certainly jobs available for second officers, but only on airlines which operate long-haul flights. Regional airlines with flights only for a 2-3 hours don't require a second officer1.
Cathy Pacific is hiring (also here). The experience of a second officer on Cathy can be read here. Aviation Job Search is listing many positions.
SO on Short-Haul
Each airline can have its own definition of second officer. What I wrote above is the general meaning. You mentioned JetA and Thomson (in comments to the deleted answer) but I couldn't find jobs for SO.
Flight Engineer
Their role is different than pilots and now they are a diminishing breed. Most of them were not pilots. Again, an airline may label a flight engineer as second officer, though Wikipedia did not mention that.

1: The aftermath of Germanwings crash can make some changes in regulations.

My former next door neighbor downgraded from Captain to Flight Engineer for Pan Am in the 70s because he had lost his medical. Although the FE PTS states "Medical Certificate Applicants must present a current second-class medical certificate or higher before taking the practical test" so maybe they changed the regs, or his medical was downgraded to Second Class


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Are aircraft separately certified for CAT III ops for +2500 feet elevation?
Is it mandatory have separate certification for aircraft operating CAT III Operations on airports having elevation more than 2500 feet? If so do that aircraft are to carry any additional equipment?
One of our airline operator has submitted a list of their aircraft which are certified for CAT III operations at airports above 2500 feet elevation. We are yet to be equipped with CAT III, hence we would like to know if we have to have any additional ground systems to enable all aircraft to operate CAT III.

Probably, CAT III is not required at 2500 ft.

Why would there be different requirements? Can you explain your thinking?

As a really wild guess, the OP has read that CAT III operations require a radar altimeter (RA), and the RA activates at 2,500ft. Therefore, how can you shoot a CAT III approach if the airport is above 2,500ft? If that's the case, he's probably confusing AGL with MSL.

Dear GdD, One of our airline operator has submitted a list of their aircraft which are certified for CAT III operations at airports above 2500 feet elevation.  We are yet to be equipped with CAT III, hence we would like to know if we have to have any additional ground systems to enable all aircraft to operate CATIII.

Denver International has Cat III approaches to all 4 north runways (35L/R, 34L/R), and I have never heard of any Cat III certification requirements specific to that airport. As far as I know, the answer to the question is "no," since nothing special happens at or near 2500' MSL that affects Cat III operations.


text:
Can we build a bigger aircraft than the A380
Can we scale up from the A380 airbus to accommodate more passengers

For the actual question body, there's Has Airbus planned to build a larger version of the A380?


text:
Are "Tally-ho" and "no joy" acceptable ATC terms for civil operations?
I keep meaning to ask this question. I heard "Tally-ho" used for the first time by a pilot on Liveatc.net. I know these are pretty standard phrases in military aviation but I wondered if civil pilots use them. Are they acceptable under either FAA or ICAO standards? If not, what's the likelihood a controller will know what you mean?

Technically no, and using one with a controller who may be unfamiliar may get you chewed out over the radio. Also I think if you use "tally-ho" you are required to buy everybody on the frequency a bottle of whiskey.

@RonBeyer Scotch or bourbon?

I'd say bourbon, Scotch is technically whisky (yes there is a difference between whiskey and whisky) :)

@RonBeyer The pilot I heard is going to need a case of it. It was a FedEx pilot right in the thick of the PM inbound rush. There may have been 30 aircraft on approach at the time. The controller sounded like an auctioneer giving out vectors.

You are allowed to yell out Tally Ho! whenever you see a fox. Do not attempt to chase the fox with the airplane.

I've never heard "tally-ho" but I do hear "no joy" from time to time and it annoys me each time.

@TylerDurden ...has that happened??

As a private pilot, I have heard "Tally-ho" and other pseudo (British?) military phrases used when talking to ATC.  I understand "Tally-ho" to be equivalent to "target(s) in sight" or "inbound" or even in some cases "affirmative", and that's the problem.  It is important to be clear and precise when communicating on the radio, however, the folks working at ATC seem to understand these phrases.
FAA:
I've read the AIM - Aeronautical Information Manual and Pilot's handbook of aeronautical knowlage (Both available for free download from the FAA's website) and I don't remember seeing these phrases anywhere.
Other texts caution against using these colorful phrases instead of standard phraseology because problems stemming from varied interpretations.  It is important to be clear and precise when communicating on the radio.
I think the correct terminology is: "Traffic In Sight" and "Negative contact"

Tally-ho should specifically mean "target in sight." It comes from fox hunting. It's what you yell when you spot the fox to send the dogs after it.

See, I learned something this morning, @TomMcW (and I appreciate that). Prior to reading your comment, I'd have thought it meant "Hello" or "Let's go", or something similar. Hence the reason for using the very clear "Traffic in sight".

@FreeMan Learned that from all the fox hunts I've been on. (...as if!)

Another correctly phrased reply: "[aircraft id] looking for traffic."

No, they aren't considered acceptable although you do hear them from time to time. Neither term is in the P/CG and the AIM 4-2-1 says:

Good phraseology enhances safety and is the mark of a professional
  pilot. Jargon, chatter, and “CB” slang have no place in ATC
  communications. The Pilot/Controller Glossary is the same glossary
  used in FAA Order JO 7110.65, Air Traffic Control. We recommend that
  it be studied and reviewed from time to time to sharpen your
  communication skills.

In other words, if it isn't in the P/CG then don't use it. Of course in reality some pilots do use military terms for whatever reason (force of habit?) but it's definitely discouraged. Apart from anything else, many pilots have no military background (or are foreigners) and have no idea what these or other slang/military phrases might mean.

"foreigners" is a relatively loose term there. He tagged it [tag:faa-regulations], but "Tally-ho" is very much a British expression, so it wouldn't make sense to those of us who are foreign to Britain/UK.

@FreeMan Yes, that was exactly my point although I've rephrased it a bit to be clearer

NO.
Not an acceptable term.
As stated earlier by others - the term has no official recognition and would only serve to confuse. Only a tiny (and rapidly diminishing) number across the globe appreciate its original 1930's context.
Some commonsense and logical analysis:
"Land Ho" means "land in sight!"
"Tally" is another word for a score - or for a count of sorts.
It follows that somebody announcing "Tally Ho" is excitedly anticipating racking up a score. This could be foxes or Messerschmitts. Of course, this only makes sense in the context of a heart-felt outburst in the heat of the moment in old England - or a place influenced by old English culture.
Use of "Tally Ho" in civil aviation makes no sense at all. How would you intend to "rack up" the score?
Tally Ho is believed to be based on a French expression from way back:
https://en.wikipedia.org/wiki/Tally-ho
It is the nature of humanity to bend language out of shape... What do you call an AERObatic machine designed by AEROnautical engineers?
Not an AEROplane?

Welcome to aviation.SE!

"No Joy" or "Tally-Ho" are not acceptable when talking on aviation bands.
Worse yet, they are not even true military terms. While "Tally" does mean you have the enemy in sight, notice there is no "Ho" attached to it.
Since you are up there and NOT shooting at people you should use the term "Visual" when you can see the aircraft being referenced. Visual is not only a military term, meaning you see a friendly but it is also used in civilian aviation and means EXACTLY the same thing.
But! It's just easier to say, "Tower, traffic in sight."
Roger, Wilco (will comply) are great words that mean things. I use them all the time.
Telling ATC your fuel is "Bingo" will get you killed, declare an emergency instead.
Fly safe! Blue skies!

Welcome to Av.SE

"Tally Ho!" was adopted by US military pilots during WWII, from British fighter pilots. Who in turn had adopted it from fox hunting. The US pilots must have just liked the sound of it, although it was an official part of the lexicon of British pilots.
They used lots of other lovely quaint terms. "Angels" for flight level, "Bogeys" for enemy aircraft. And the Navy had a particular anti-submarine manoeuvre they called "Raspberry"! Nothing like some jolly fun during a war old boy.
You still hear "Tally Ho" used by military pilots on both sides of the Atlantic, with the same meaning it had in WWII.

interesting information, but not really an answer

They aren't "quaint" terms, but are pulled from military terminology that IS approved for use in the air:
https://en.wikipedia.org/wiki/Multiservice_tactical_brevity_code
Example: No Joy, Bogey, Angels

No. Brevity codes are for use with other military aircraft. They're not approved (in whatever sense terminology for civilian use is approved) for use by civil aircraft in communication with ATC.  They're official terms in one context, but they aren't approved, nor appropriate, in a civil context.


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Why does the U.S. keep thousands of retired aircraft in storage?
A view of Davis-Monthan AFB shows thousands of retired aircraft sitting in the desert.

They go through great lengths to preserve them, even sealing them with an opaque white, hi-tech vinyl plastic compound called "spraylat."

Such an enormous stash of aircraft makes me wonder what they're being kept for. I'm sure there are a few uses for some of them but certainly not all of them. There can't be a big demand for spare parts from obsolete planes. It seems like they would want to scrap them.
Are they being kept in case there is some sort of all-out war and they need cobble together a bunch of F-4's and C-141's to support the air force? Would that even be feasible?
Does it somehow cost more to scrap them than the materials are worth?
Why are they keeping so many retired planes?

Photos retrieved from airplaneboneyards.com

Yes, spare parts, not just for the US, but to anybody that we sold those aircraft to. Also some of them are stored in a way that makes them relatively easy to put back in service, like the F15 in the second picture. Not sure they would need to go back as far as the F4, but the F15 is still in service, and still being built until 2019. It has been in service for 44 years at this point, making parts for older aircraft hard to find yet valuable.  See this 309th Boneyard article on Wikipedia.

@Ron Beyer I can understand ones like the F-15 which are still in service. Even a few of the older ones for spare parts. But they have row after row of things like F-4's and C-141's that are no longer in use.

@RonBeyer - Well QF-4s don't grow on trees :P btw, that's a F-14

Some aircraft sold or loaned to outside military forces are built in batches. These aircraft stay in service for a longer period of time than those in the advancing military power, making spares very difficult to obtain and replacement aircraft for those lost in action are going to be impossable to get. I remember on 19 Squadron in RAFG Wildenrath (1979/82), the F4 Phantom was very demanding on which panels and parts would swop between aircraft. The Phantom also went through many states of evolution and when our Govenment decided it was cheaper to buy more F4 aircraft, they had to consider the spares, fitment and training that would be needed to keep our units similar. The Phantoms that were purchased I believe came from the boneyard.
Of course, the 'all out war' theroy also holds true, if a planet size war was to break out, and you recall all your old pilots.... easier to shove them in aircraft they flew 30-40 years ago than train them in the newer stuff.... going to get very messy up there and replacing pilots/ planes will be a priority, numbers can sometimes win wars. Life expectancy of our frontline pilots were 2/3 sorties at best, Ground crew in fixed bases were 2 days at most..... I miss the old days.


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Why do black boxes seem so outdated?
Now that the Malaysian flight was again in the news, that they had officially given up and stopped searching, this issue comes to mind again.
Why do w all depend on finding a physical recorder, and why is it so hard to find?

Why isn't the system updated so that the flight recorder can live stream all its info back to the manufacturer?
Why does it only give off sonar signals and not high frequency electromagnetic broadcasts which, I would imagine, would be far easier to find?

I would suspect something along the line of system simplicity.

@SMSvonderTann That would be simple, until you gotta find that thing.

You've asked two separate questions at once, which is frowned on in the Q&A site format. One has already been discussed at length here. Not sure about the other. Maybe consider Why don't black boxes have their own GPS?

Sounds like the second question is addressed here: Why don't black boxes send a signal when above water?

"[why] not high frequency electromagnetic broadcasts". Because this is better done by the ELT. But radio signals don't propagate in water, so for water there is the ultrasonic ULB.

I think most of the comments aren't really understanding the question, at least as I'm understanding it.  Which is why not stream everything that the "black box" records to a satellite instead of reccording it on a piece of hardware that may never be found?  I think the answer is twofold: bandwidth limitations (though I'm not sure of that), and most importantly, government regulations that say you have to use the "black box".

This should be split into two questions as mentioned. The First one is addressed elsewhere on this site but the second one is worth noting.

Why does it only give off sonar signals and not high frequency
  electromagnetic broadcasts which, I would imagine, would be far easier
  to find?

The short answer: high frequency waves don't propagate through water very well (or very far for that matter).
This in turn prevents underwater signal broadcasting units from using any kind of high frequency wave. Thus you need to operate in the audible or just above audible range to get effective underwater range. Subsequently the Shannon Theorem limits how much data can be bussed over a low frequency wave. As such black boxes can often do nothing more than emit a simple ping.

The quoted question asks about high frequency EM waves, while your link refers to acoustical waves.

Communication with submarines

@BowlOfRed, the same applies to EM, only more so.  Radio communication with submarines is done using single-hertz radio frequencies.

@BowlOfRed: Just to give an idea: the antenna for a ground station for communication with submarines is typically about 60km(!!!) long, and the ground stations typically have their own power plant(!!!). And what about the other direction? Well, actually, submarines can't answer, it is simply impossible to put an ELF transmitter on a submarine (which after all is huge and has its own nuclear power plant), so obviously it is even more infeasible to put in a small FDR/CVR.

@JörgWMittag Thanks. Although I found this idea among answers referenced by fooot I didn't see this issue directly addressed.